Solve for $a$, $- \dfrac{a + 8}{4a + 1} = 3$
Answer: Multiply both sides of the equation by $4a + 1$ $ -(a + 8) = 3(4a + 1) $ $-a - 8 = 12a + 3$ $-8 = 13a + 3$ $-11 = 13a$ $13a = -11$ $a = -\dfrac{11}{13}$